Everything in the course tables, in a form that can live outside the site. JSON is the complete record. Markdown is the readable one.
Every text box takes a small set of marks. Nothing else, and never raw HTML.
**bold** and *italic* and `code`. A link is [the words](https://example.com). A blank line starts a new paragraph.
Citations. {{cite:SOURCE-ID}} puts a numbered reference in the text and the source in the reference list. Add pages with {{cite:SOURCE-ID|pp. 12-14}}. Use the "Insert citation" picker rather than typing ids.
Footnotes. {{fn:The note itself, which may contain a [link](https://...)}}.
Link to a source without citing it: {{source:SOURCE-ID|the words to show}}.
Green Book prompt. {{gb:Swamp Thing #1}} gives the reader a link that opens a new Green Book entry with that title.
Blocks. Paragraph, heading, quotation (with attribution and an optional cited source), list, table, image, video (YouTube or Vimeo link), callout (note, context, think, task, take care, or "record your own thoughts first") and a divider.
Publishing. Draft is hidden. Scheduled goes live at the time you set. Published is live. A lesson ticked "public sample" can be read by anyone; every other published lesson needs a signed in learner. A module set to "coming" is listed on the course page but cannot be opened.
Assignments. Fix a typo with "Save correction". If the question or the requirements change, use "Save as new version": learners who have already started keep the brief they were given.
Sources. Everything a lesson reads should be a source record with where to buy, borrow or read it legally. Leave "requires verification" on until you have checked the details yourself.